The present invention relates to systems and methods used in down hole applications. More particularly, the present invention relates to a secondary or contingency system for initiating a down hole operation such as opening a cementer or setting a down hole tool when a primary system for initiating the down hole operation fails.
In the course of treating and preparing a subterranean well for production, down hole tools, such as well packers, are commonly run into the well on a tubular conveyance such as a work string, casing string, or production tubing. The purpose of the well packer is not only to support the production tubing and other completion equipment, such as sand control assemblies adjacent to a producing formation, but also to seal the annulus between the outside of the tubular conveyance and the inside of the well casing or the wellbore itself. As a result, the movement of fluids through the annulus and past the deployed location of the packer is substantially prevented.
Well packers are designed to be set using a variety of methods, including electronics, pressure-setting, mechanical shifting, and the like. Although the specific reasons can vary, these well packers are each subject to failure or malfunction. The time and effort required to deal with such failures can be extremely costly.
In addition to the setting of well packers, cementing operations often involve the shifting of one or more internal sleeves to open or otherwise expose ports or passageways in the casing string to allow cement slurry to flow from the interior of the casing into the annulus between the casing wellbore. As with the setting of a well packer, when a cementing operation fails, costly time and effort may be required to send specialized plugs or other machinery down the well to complete the operation.